A banknote handling device such as an automated teller machine (ATM) includes a banknote storing device that temporarily stores input banknotes. Such a banknote storing device includes a banknote separating device that separates and sends out stacked banknotes sheet by sheet after the banknotes are stored.
FIG. 12 is a schematic diagram illustrating an operation of conveying banknotes using a separation roller and a sending roller in a conventional banknote separating device. As illustrated in FIG. 12, a conventional banknote separating device 111 includes a set of separation roller 116 and sending roller 117 that are used to separate and send out banknotes 102 stacked in a storage unit 114 sheet by sheet. In the banknote separating device 111, banknotes 102 are sent along a conveyance passage 114b from a sending port 114a of the storage unit 114. At this time, the plural banknotes 102, sent from the sending port 114a to the separation roller 116, are sent in a state in which the banknotes are shifted in positions and overlapped in a step shape in a direction in which the banknotes approach the separation roller 116. In the banknote separating device 111, when the plural banknotes 102 stacked in the storage unit 114 are separated sheet by sheet, a leading edge of the banknote 102, moving to the separation roller 116, comes in contact with a circumferential surface of the separation roller 116. The leading edge of the banknote 102 is sent to a contact portion 120, in which the separation roller 116 and the sending roller 117 contact each other, by a frictional force between the overlapped banknotes 102 after coming in contact with the circumferential surface of the separation roller 116. By causing the sending roller 117 to rotate relative to stationary separation roller 116, the banknote 102, sent to the contact portion 120, is conveyed through the contact portion 120 and is set to the outside of the banknote separating device 111.
As a roller which is used to convey banknotes, a configuration in which a rubber ring is attached to a ring groove formed on the circumferential surface of a reference roller formed of metal is known. The reference roller having this configuration is used to convey a banknote, which is interposed between a detection roller and the reference roller, in a thickness detecting unit that detects a thickness of the banknote.
Patent Literature 1: Japanese Laid-open Patent Publication No. 2014-47073
The entire circumferential surface of the separation roller 116, which is used in the conventional banknote separating device 111, is formed of a rubber material and a high friction coefficient is secured in the entire circumferential surface to prevent plural banknotes 102 from being overlapped and conveyed to the contact portion 120 with the sending roller 117. The width in the axial direction A (see FIG. 15) of the separation roller 116 is larger than the width of the sending roller 117. Accordingly, in the contact portion 120, the circumferential surface of the sending roller 117 comes in contact with a central portion in the axial direction (the width direction) A of the circumferential surface of the separation roller 116.
In general, in the banknote separating device 111, since the leading edges of banknotes 102, moving from the storage unit 114, come into contact with the circumferential surface of the separation roller 116 at a contact point P1 in the vicinity of the contact portion 120, the overlap of the banknotes 102 is suppressed, the leading edge of one banknote 102 is guided to a contact point P0 of the contact portion 120, and the banknote 102 is appropriately sent out. However, the sending port 114a of the storage unit 114 is formed to be larger than the thickness of the banknote 102 and the length thereof in the long-side direction to smoothly send the banknote 102 from the inside of the storage unit 114. Accordingly, in the banknote separating device 111, the leading edge of the banknote 102, moving from the storage unit 114, may come in contact with the circumferential surface of the separation roller 116 at a contact point P2 separated to the storage unit 114 side from the vicinity of the contact portion 120 as illustrated in FIG. 12. In this case, since the separation roller 116 is formed of rubber, the frictional force between the banknote 102 and the circumferential surface of the separation roller 116 may act greatly on the leading edge of the banknote 102 to stop movement of the banknote 102. As a result, there is a problem in that the banknote 102 is guided in an abnormal state to between the separation roller 116 and the sending roller 117 to cause a paper jam (hereinafter, referred to as a jam).
In addition, in the conventional banknote separating device 111, when the leading edge of the banknote 102 comes in contact with an edge on the end face sides of both end portions in the axial direction A of the separation roller 116, the banknote 102 may stop by the frictional force with the edge or skewing, in which the banknote 102 is obliquely send in the appropriate sending direction of the banknote 102, may occur. As a result, there is a problem in that the skewing banknote 102 is guided between the separation roller 116 and the sending roller 117 to cause a jam.
As a countermeasure against this problem, a configuration using a roller cover that guides movement of the leading edge of a banknote 102, has been proposed. FIGS. 13 and 14 are a perspective view and a cross-sectional view illustrating a metal plate of a roller cover which is disposed in a banknote separating device according to a related art. FIG. 15 is a perspective view illustrating a separation roller and a metal plate which are disposed in the banknote separating device according to the related art.
As illustrated in FIGS. 13 and 14, a banknote separating device 211 according to the related art includes a roller cover 131 that guides the leading edge of a banknote 102, moving from the storage unit 114 to the contact portion 120. The roller cover 131 includes a guide portion 132 formed of a resin and a metal plate 133 which is supported by the guide portion 132. The roller cover 131 is disposed adjacent to the storage unit 114 to cover the separation roller 116. The guide portion 132 extends from the inside of the storage unit 114 to the vicinity of the separation roller 116 and includes a curved surface 132a which is curved along the circumferential surface of the separation roller 116. A banknote 102, stacked in the storage unit 114, is guided to the vicinity of the separation roller 116 along the curved surface 132a of the guide portion 132. As illustrated in FIGS. 14 and 15, the metal plate 133 is disposed to be curved along the circumferential surface of the separation roller 116. The metal plate 133 covers a range from an end portion on the storage unit 114 side to the vicinity of the contact portion 120 on the circumferential surface of the separation roller 116. Accordingly, the metal plate 133 prevents the leading edge of a banknote 102 from coming in contact with the circumferential surface of the separation roller 116 at a position closer to the storage unit 114 side.
FIG. 16 is a schematic diagram illustrating an operation of conveying a banknote 102 using the separation roller 116 and the sending roller 117 in the banknote separating device 211 according to the related art. As illustrated in FIG. 16, the leading edge of a banknote 102, moving to the circumferential surface of the separation roller 116, slides over the outer surface of the metal plate 133 in the range from the storage unit 114 side to the vicinity of the contact portion 120, and the leading edge of the banknote 102 is guided to the contact portion 120 along the circumferential direction of the separation roller. Even when the leading edge of the banknote 102 moves to the circumferential surface of the separation roller 116 at the contact point P2 closer to the storage unit 114, the leading edge of the banknote 102 slides over the metal plate 133 and is guided to the contact point P1 and thus is smoothly guided to the contact point P0 of the contact portion 120. Accordingly, the metal plate 133 of the roller cover 131 assists appropriate separation of the banknotes 102. In this way, the metal plate 133 prevents the banknote 102 from being stopped by locking the leading edge of the banknote 102 to the circumferential surface of the separation roller 116 by the frictional force between the leading edge of the banknote 102 and the circumferential surface of the separation roller 116 to interfere with movement of the banknote 102.
The metal plate 133, which is used in the banknote separating device 211 according to the above-mentioned related art, has a thickness of about 0.2 mm and is curved in a desired arc shape along the circumferential surface of the separation roller 116. It is thought that such a metal plate 133 is molded using a resin material, but in molding of a resin material, it is difficult to form the resin material with the same small thickness as the metal plate 133 and to form the resin material in a shape in which a tip thereof is sharp like the end portion of the metal plate 133. In order to cause the metal plate 133 to maintain such predetermined rigidity not to be bent by collision with a banknote 102, both sides of the metal plate 133 in the axial direction of the separation roller 116 are fixed to the guide portion 132. Accordingly, the banknote separating device 211, using the metal plate 133, causes an increase in manufacturing cost by forming the metal plate 133 in a desired arc shape and attaching the metal plate to the guide portion 132.
From the viewpoint of satisfactorily preventing skewing or jam at the time of separation of a banknote 102, it is preferable that an area from the storage unit 114 side to the vicinity of the contact portion 120 on the circumferential surface of the separation roller 116 be covered with the metal plate 133. On the other hand, in the banknote separating device 211, when a jam occurs, a banknote 102 is removed from between the separation roller 116 and the sending roller 117 by reversely conveying the banknote 102 in the direction opposite to the input direction of the banknote 102. Accordingly, when the range, in which the circumferential surface of the separation roller 116 is covered with the metal plate 133, is extended to the vicinity of the contact portion 120, the trailing edge of the banknote 102 is easily locked to the metal plate 133 at the time of reversely conveying the banknote 102. As a result, the metal plate 133 is easily turned by the reversely conveyed banknote 102 and it is difficult to smoothly remove the locked banknote 102. Accordingly, an adjustment operation of positioning the metal plate 133 at a predetermined position in the circumferential direction of the separation roller 116, that is, an operation of appropriately adjusting a range in which the circumferential surface of the separation roller 116 is covered with the metal plate 133, in consideration of this influence becomes troublesome, thereby causing an additional increase in manufacturing cost.
In addition, in order to prevent a banknote 102 from being stopped when the leading edge of the banknote 102 comes in contact with the edge of the separation roller 116, a countermeasure of performing a chamfering process (an R chamfering process) of rounding the edges on both end face sides of the separation roller 116 in an arc shape, has been employed. However, the R chamfering process of the edges on both end face sides is performed for each separation roller 116 and thus the processing cost also increases.
As described above, in the banknote separating device 211 according to the related art, it is possible to prevent skewing of banknotes 102 or a jam of banknotes 102, by forming a part of the roller cover 131 out of the metal plate 133, by adjusting the position of the metal plate 133, and by performing the R chamfering process of the edges of the separation roller 116. However, this series of processes causes an increase in manufacturing cost.
When the reference roller described in Patent Literature 1 is used as the separation roller, the rubber ring, protruding from the circumferential surface of the reference roller, comes in contact with a banknote, but the circumferential surfaces on both sides of the rubber ring do not easily come in contact with the banknote well. Accordingly, with the reference roller, there remains a problem that the leading edge of a banknote is not made to slide over the circumferential surface of the reference roller and the banknote skews, and an effect of preventing a jam is not achieved. Accordingly, in the technique described in Patent Literature 1, banknotes are not appropriately separated and it is not proper to employ the reference roller as the separation roller.